Since 1976, when Propionibacterium acnes was demonstrated to be uniformly sensitive to the antibiotics used in the treatment of acne, an increasing number of patients with antibiotic-resistant propionibacteria have been described. In a recent British study,1 cultures of propionibacteria were taken from 468 patients with acne. All patients had received courses of antibiotics in the past; 155 patients had acne that was unresponsive to treatment for at least 3 months. Nearly half of the 468 patients had propionibacteria strains that were resistant to one or more antibiotics; erythromycin resistance was most common (124 patients). All 61 patients with propionibacteria strains that were resistant to tetracycline also showed resistance to doxycycline, but none showed resistance to minocycline. Twenty-seven patients had two or more propionibacteria strains with different antibiotic resistances. The patients who showed a response to antibiotics in this study did not harbor antibiotic-resistant propionibacteria strains.